New functions STR_SUBSTRING_AFTER/BEFORE

src/main/java/com/ezylang/evalex/config/ExpressionConfiguration.java

@@ -57,6 +57,8 @@
 import com.ezylang.evalex.functions.string.StringMatchesFunction;
 import com.ezylang.evalex.functions.string.StringRightFunction;
 import com.ezylang.evalex.functions.string.StringStartsWithFunction;
+import com.ezylang.evalex.functions.string.StringSubstringAfterFunction;
+import com.ezylang.evalex.functions.string.StringSubstringBeforeFunction;
 import com.ezylang.evalex.functions.string.StringSubstringFunction;
 import com.ezylang.evalex.functions.string.StringTrimFunction;
 import com.ezylang.evalex.functions.string.StringUpperFunction;
@@ -280,6 +282,8 @@ public class ExpressionConfiguration {
           Map.entry("STR_RIGHT", new StringRightFunction()),
           Map.entry("STR_STARTS_WITH", new StringStartsWithFunction()),
           Map.entry("STR_SUBSTRING", new StringSubstringFunction()),
+          Map.entry("STR_SUBSTRING_AFTER", new StringSubstringAfterFunction()),
+          Map.entry("STR_SUBSTRING_BEFORE", new StringSubstringBeforeFunction()),
           Map.entry("STR_TRIM", new StringTrimFunction()),
           Map.entry("STR_UPPER", new StringUpperFunction()),
           // date time functions

src/main/java/com/ezylang/evalex/functions/string/StringSubstringAfterFunction.java

@@ -0,0 +1,51 @@
+/*
+  Copyright 2012-2024 Udo Klimaschewski
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+package com.ezylang.evalex.functions.string;
+
+import com.ezylang.evalex.EvaluationException;
+import com.ezylang.evalex.Expression;
+import com.ezylang.evalex.data.EvaluationValue;
+import com.ezylang.evalex.functions.AbstractFunction;
+import com.ezylang.evalex.functions.FunctionParameter;
+import com.ezylang.evalex.parser.Token;
+
+/**
+ * Returns the substring after the first occurrence of another (separator) string, or an empty
+ * string if the first string does not contain the second string.
+ *
+ * <p>For example: {@code STR_SUBSTRING_AFTER("2024/07/15", "/")} returns {@code "07/15"}.
+ *
+ * @author oswaldobapvicjr
+ */
+@FunctionParameter(name = "string")
+@FunctionParameter(name = "separator")
+public class StringSubstringAfterFunction extends AbstractFunction {
+  private static final String STR_EMPTY = "";
+
+  @Override
+  public EvaluationValue evaluate(
+      Expression expression, Token functionToken, EvaluationValue... parameterValues)
+      throws EvaluationException {
+    String string = parameterValues[0].getStringValue();
+    String separator = parameterValues[1].getStringValue();
+    return expression.convertValue(substringAfter(string, separator));
+  }
+
+  private String substringAfter(String string, String separator) {
+    int position = string.indexOf(separator);
+    return (position == -1) ? STR_EMPTY : string.substring(position + separator.length());
+  }
+}

src/main/java/com/ezylang/evalex/functions/string/StringSubstringBeforeFunction.java

@@ -0,0 +1,49 @@
+/*
+  Copyright 2012-2024 Udo Klimaschewski
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+package com.ezylang.evalex.functions.string;
+
+import com.ezylang.evalex.EvaluationException;
+import com.ezylang.evalex.Expression;
+import com.ezylang.evalex.data.EvaluationValue;
+import com.ezylang.evalex.functions.AbstractFunction;
+import com.ezylang.evalex.functions.FunctionParameter;
+import com.ezylang.evalex.parser.Token;
+
+/**
+ * Returns the substring before the first occurrence of another (separator) string, or the original
+ * string if it does not contain the second string.
+ *
+ * <p>For example: {@code STR_SUBSTRING_BEFORE("2024/07/15", "/")} returns {@code "2024"}.
+ *
+ * @author oswaldobapvicjr
+ */
+@FunctionParameter(name = "string")
+@FunctionParameter(name = "separator")
+public class StringSubstringBeforeFunction extends AbstractFunction {
+  @Override
+  public EvaluationValue evaluate(
+      Expression expression, Token functionToken, EvaluationValue... parameterValues)
+      throws EvaluationException {
+    String string = parameterValues[0].getStringValue();
+    String separator = parameterValues[1].getStringValue();
+    return expression.convertValue(substringBefore(string, separator));
+  }
+
+  private String substringBefore(String string, String separator) {
+    int position = string.indexOf(separator);
+    return (position == -1) ? string : string.substring(0, position);
+  }
+}

src/test/java/com/ezylang/evalex/functions/string/StringFunctionsTest.java

@@ -202,6 +202,37 @@ void testMatches(String expression, String expectedResult)
     assertExpressionHasExpectedResult(expression, expectedResult);
   }
 
+  @ParameterizedTest
+  @CsvSource(
+      delimiter = ':',
+      value = {
+        "STR_SUBSTRING_AFTER(\"myFile.json\", \".\") : json",
+        "STR_SUBSTRING_AFTER(\"2024/07/15\", \"/\") : 07/15",
+        "STR_SUBSTRING_AFTER(\"2024/07/15\", \"20\") : 24/07/15",
+        "STR_SUBSTRING_AFTER(\"test\", \"\") : 'test'",
+        "STR_SUBSTRING_AFTER(\"test\", \"a\") : ''",
+        "STR_SUBSTRING_AFTER(\"\", \"\") : ''"
+      })
+  void testSubstringAfter(String expression, String expectedResult)
+      throws EvaluationException, ParseException {
+    assertExpressionHasExpectedResult(expression, expectedResult);
+  }
+
+  @ParameterizedTest
+  @CsvSource(
+      delimiter = ':',
+      value = {
+        "STR_SUBSTRING_BEFORE(\"myFile.json\", \".\") : myFile",
+        "STR_SUBSTRING_BEFORE(\"2024/07/15\", \"/\") : 2024",
+        "STR_SUBSTRING_BEFORE(\"test\", \"\") : ''",
+        "STR_SUBSTRING_BEFORE(\"test\", \"a\") : 'test'",
+        "STR_SUBSTRING_BEFORE(\"\", \"\") : ''"
+      })
+  void testSubstringBefore(String expression, String expectedResult)
+      throws EvaluationException, ParseException {
+    assertExpressionHasExpectedResult(expression, expectedResult);
+  }
+
   @ParameterizedTest
   @CsvSource(
       delimiter = ':',